The Straightness Backstroke Kick Makes Fast Speed and Increased Lactate Acid. A Case Study Using 3-Times Olympian

In this study, we assess the effectiveness of utilizing a straight knee kick in the backstroke with regard to the overall time, max speed, and distance per stroke when using a straight knee butterfly technique. We analyzed freestyle kick of knee angles from 7-Olympic medalists, 1970＇s S-shaped pulling pattern stroke was used with a bending knee freestyle kick. The straight knee kick used in butterfly competitions resulted in improvements from 54.74 to 51.00 in Men＇s 100-meter butterfly and fi＇om 23.43 to 23.02 in Men＇s 50-meter butterfly. Using a straight knee kick in backstroke competitions resulted in improvements from 1：01.74 to 1：00.55 in the 100-meter backstroke event. Increases in performance speed, max speed and distance per stroke among three elite level swimmers are highly correlated to duration of the kick resistance, and straight knee kick in backstroke. The straight knee kick also resulted in an increase in lactate acid.

The Downward Breaststroke Kick Makes Fast Speed and Increased Lactate Acid

In this study,we assess the effectiveness of utilizing a downward breaststroke kick with regard to the overall time,max speed and velocity per stroke when using a downward breaststroke kick technique.We analyzed breaststroke kick of knee angles from 8 elite world class swimmers.The downward breaststroke kick used in breaststroke competitions resulted in improvements average of 100 yard or 100 meter breaststroke from 1:05.10 s to 1:01.97 s.Increases in performance max speed and velocity per stroke among 9 elite world class swimmers are highly correlated to duration of the kick aerodynamic buoyant farce in breaststroke.The downward breaststroke kick also resulted in an increase in lactate acid.

Optimizing dietary lipid use to improve essential fatty acid status and reproductive performance of the modern lactating sow:a review

Dietary lipid supplementation benefits the prolific and high-producing modern lactating sow. A comprehensive review of recent studies showed that lipid supplementation increases average daily energy intake, which is partitioned for lactation as indicated by greater milk fat output and improved litter growth rate. Recent compelling findings showed that addition of particular lipids during lactation improved the subsequent reproductive outcome of sows. Such benefits were related to the level of dietary essential fatty acids（EFA, linoleic acid, C18：2n-6; and α-linolenic acid, C18：3n-3） during lactation. Lactation diets without supplemental EFA resulted in a pronounced negative balance（intake minus milk output） of linoleic（-25.49 g/d） and α-linolenic acid（-2.75 g/d）; which compromised sow fertility（farrowing rate 〈 75 % and culling rates 〉 25 % of weaned sows）. This phenomenon seems to be increasingly important with advancing sow age because of a progressive reduction of body EFA pool over successive lactations. The net effect of supplemental EFA during lactation was to create a positive EFA balance, which improved the subsequent reproduction of sows. Adequate linoleic acid intake improved the proportion of sows that farrowed in the subsequent cycle（Farrowing rate（%） = [（-1.5 × 10^-3× linoleic acid intake（g/d）^2） ＋（0.53 × linoleic acid intake（g/d）） ＋（45.2）]; quadratic P = 0.002, R^2= 0.997, RMSE = 0.031）. In addition, increasing linoleic acid intake increased the number of pigs born in the subsequent cycle（total pigs born（n） = [（9.4 × 10^-5× linoleic acid intake（g/d）^2） ＋（0.04 × linoleic acid intake（g/d）） ＋（10.94）]; quadratic P = 0.002, R^2= 0.997, RMSE = 0.031）. Supplemental α-linolenic acid resulted in a rapid return to estrus（sows bred： sows weaned = 94.2 %; wean-to-estrus interval = 4.0 d） and achieved a high retention of pregnancy（sows pregnant： sows bred = 98 %）. Collectively, we conclude that a minimum dietary intake of10 g/d of α-linolenic acid, simultaneous with a minimum of 125 g/d of linoleic acid should be provided to ≥ 95 % of the sows; thereby, achieving a maximum sow reproductive efficiency through multiple mechanisms that include rapid return to estrus, high maintenance of pregnancy and large subsequent litter size in mature sows, that appear to be susceptible to EFA deficiency.

The interaction between end-metabolites and immune escape

Emerging data from metabolites-relating trails in cancers demonstrate that a common mechanism of resistance to many novel classes of immune therapeutics is the emergence of immune escape due to the reprogramming of cellular metabolism.Among them,current work about end-metabolites mostly focuses on the intersection between lactate acid,adenosine,reactive oxygen species(ROS),and tumour immune escape.In this article,we aim to review the evidence to date for the dynamic interplay between the three end-metabolites and tumour immune escape for potential approaches to overcome obstacles in the efficacy and durability of immune cancer therapies.We have organized known end-metabolites-associated immune escape mechanisms into three hallmarks:(1)decreased immunogenicity of cancer cells which constitutes defective antigen presentation and the attenuated expression of costimulatory molecules on tumour cells,(2)immunosuppressive microenvironment with aberrant angiogenesis inhibits the differentiation,maturation,and immune deviation of immune cells while drives the activation of immunosuppressive cells by immune-suppressive mediators(cytokines and other factors),(3)immune tolerance retained by inhibitory molecules and depletion of immune cells.

Influence of Intravenous Injection of Hydroxyapatite on Mouse Movement Ability

Lactic acid is usually formed during strenuous exercise, and a large amount of lactic acid and slow anaerobic glycolysis in muscle lead to limitations of movement ability. Hydroxyapatite（HAp） is an alkaline inorganic material with a good biocompatibility. It slowly degrades in vivo and releases trace amounts of calcium ions, reducing cell damage by reacting with polylactic acid and neutralizing local acid environment. Whether HAp can reduce the concentration of lactic acid in vivo and improve movement ability is not yet clear. Here, after eight days of training, 40 mice were randomly divided into four groups： control, distilled water, sodium bicarbonate and HAp group. After one day of rest, the mice were intravenously injected via the lateral tail veins with 1 ml distilled water, sodium bicarbonate and HAp suspension（2.2 mg/ml）, respectively, and subjected to a swimming exhaustive experiment（load 10%）. The swimming time of mice in the water, under water and total time were recorded. The exhaustive exercise mice were immediately subject to abdominal cavity anaesthesia. The concentrations of blood, gastrocnemius and myocardial lactic acid as well as serum LDH activity were detected. We demonstrate that HAp can significantly prolong swimming time and improve serum LDH activity, but does not affect lactic acid concentration. In conclusion, intravenous injection of HAp nanoparticles can significantly improve the exhaustive swimming ability of mice mainly because of the elevated blood LDH activity induced by HAp.

Role of rno-miR-124-3p in regulating MCT1 expression in rat brain after permanent focal cerebral ischemia

This study aimed to assess the role of microRNAs(miRNAs)in regulating monocarboxylate transporter-1(MCT1)expression in rat brain after permanent focal cerebral ischemia to identify a new target for early treatment of cerebral ischemia.Focal cerebral ischemia was induced by permanent middle cerebral artery occlusion(pMCAO)in rats.Morphology and protein expression levels of MCT1 were assessed by immunofluorescence and Western blotting.Using bioinformatics and double luciferase reporter assays,rno-miR-124-3p was selected as a direct target for rat MCT1.Expression of rno-miR-124-3p after pMCAO was detected.Then,rats were treated with rno-miR-124-3p agomir via lateral ventricle injection,and after 6 h or 24 h ischemia,rno-miR-124-3p expression and gene and protein expression of MCT-1 were detected by qRT-PCR and Western blotting.Brain infarction was identified by 2,3,5-triphenyltetrazolium chloride(TTC)staining.Results showed that pMCAO induced brain infarction and increased the expression of MCT1.The levels of rno-miR-124-3p after pMCAO were in contrast to those of MCT1 protein in ischemic region,while declined after 3,6 and 12 h of pMCAO in ischemic penumbra.After administration of rno-miR-124-3p agomir,MCT1 mRNA and protein levels were increased after 6 h of pMCAO,while decreased after 24 h of pMCAO.Meanwhile,rno-miR-124-3p levels increased after both times.TTC staining showed treatment with rno-miR-124-3p agomir reduced brain infarction.The role of rno-miR-124-3p in regulating MCT1 was as a positive regulator after 6 h of pMCAO,while a negative regulator after 24 h of pMCAO,however,both activities had protective effects against cerebral ischemia.